People equate the presence of [^\w\s] characters with "unreadable", because they require some prior knowledge to interpret. On the other hand they argue that the absence of such non-word characters means that everything has a proper name, which makes code understandable without knowing the programming language.

So even if you show them a piece of very clean Perl code, some people just notice the presence of sigils, and refuse to even try to understand what the code does.